Test analysis: Xiao Zhang's "implicit criticism" is his dissatisfaction with Xiao Li's lateness, but it is very euphemistic. Therefore, you can't directly express your dissatisfaction with words such as "unpunctuality" and "no credit", but you can euphemistically say that you have waited too long and so on. Xiao Li's "humorous response" should emphasize humor and imply apology and sincerity.